Many electronic systems include circuits that provide fixed functionality. For instance, a signal processing device can include fixed function circuits, such as signal filters and analog-to-digital converters, to perform signal processing operations. By arranging these fixed-function circuits in particular configurations, electronic systems can be built to perform specific tasks.
Programmable electronic systems include more generalized circuits or blocks, such as digital and analog programmable blocks, that can be (re)programmed to implement a large number of peripherals. The digital blocks can include programmable circuitry configured to provide various digital functions. The analog blocks can be used for development of analog elements, such as analog filters, comparators, inverting amplifiers, as well as analog-to-digital and digital-to-analog converters. A programmable interconnect allows the analog and digital blocks to be combined to form a wide variety of functional modules.
The programmable analog blocks commonly implement one of continuous-time functions or discrete-time functions. Thus, system designers build programmable electronic systems to include programmable digital blocks, programmable analog continuous-time blocks, programmable discrete-time blocks, as well as various fixed function circuits.